Sir,

Noticing your request in Ag^l. Gazette of 15^th. inst, as to the proportion of sexes in domestic animals I willingly contribute a mite.¹

I have a sheep farm in the west Highlands consisting of Black faced stock. I had noticed that I have always a larger number of ewe lambs than of Tup. After seeing your note I wrote a neighbour of mine there of long and extensive experience. I have just had his answer which confirms my own experience. He writes that the ewes predominate over the Tup lambs on an average to the extent of 12 per cent. This he says may be held as true for the Black faced sheep over the Highlands.² The pasturage is poor, consisting of heath and coarse mountain grasses. The stocks go on the hills all winter and are often pinched for food during snow storms. Twin lambs are in small numbers and 3 at a birth is very rare. I have often asked the question of myself “Does scanty fare tend to produce more Ewe Lambs?

Among stocks of pure Leicester sheep which are all high fed the sexes may be assumed as nearly equal.—even where from $\frac{2}{3}$ ^rd. to $\frac{3}{4}$ of the Ewes produce 2 at a birth and $\frac{1}{10}$ ^th. three

As regards the other domestic animals I could not give you any reliable information.

I take this opportunity of sending you a paper of mine on certain conditions that favour the growth and predominance of plants. You will observe that at page 22 I came pretty close upon your “law of competition” or “Natural Selection.” before your work appeared.³ Baron Liebig⁴ adopted and acknowledge the views I put forth here. I discussed the conditions that favour the predominance of trees in my work on “North America”.⁵

I assure you that I derived great pleasure from the work “Origin of Species”.

with much esteem | I am | Your most obd Ser^t. | Robert Russell

P.S. In this part of the country I have been informed that among Partridges the Cock-birds are considerably more than double those of the hen-birds in number.

R.R.